I'm trying to find a way to keep a value through multiple rows of information in script. I tried firstvalue & lastvalue, but it doesnt help because i potentially have duplicates (that should be there). I have a scenario where a person works on a reference, and can choose to close and work on this item about 2 hours later, however someone else can also work on this item as well. I need to keep the first time he worked on this item and stopped, and thereafter start a new calculation when he works on it again.

I need to carry the start value till the end as per column 'start' in the example above? Note person B can start and end the reference twice in a day, but there will be a other references in between (so he wont start the item a second time, without references in between). I believe peek could work, but im struggling to keep a value through all rows as the number of rows vary...

Would really appreciate the assistance on how to achieve this in script..